Yushchenko said late Sunday that he welcomes the decision by Ukrainian prosecutors to re-open the criminal investigation.
But he said he hopes prosecutors will delay establishing the truth until after the 26 December rerun of the runoff election against Prime Minister Viktor Yanukovych.
Yushchenko reiterated that he believes there was official involvement in the poisoning, which has left him disfigured.
"I am convinced that this [poisoning] is the work of those in power, absolutely convinced," Yushchenko said. "Time is now needed for the investigation. A lot of the circumstances are already known. I think if the Prosecutor-General's Office acts according to Ukraine's laws, both the country and the world at large will know soon who did this."
Yushchenko was speaking after his return to Kyiv from Vienna, where Austrian doctors said there was "no doubt" he had been the victim of poisoning by the toxic chemical dioxin.
In Brussels, EU spokeswoman Emma Udwin today said the finding by doctors in Vienna that Yushchenko was deliberately poisoned is "very disturbing." She said anyone found to have deliberately poisoned Yushcbenko must be brought to justice.
(Reuters/AP/AFP)[For more RFE/RL coverage and analysis of the political crisis in Ukraine, click here.]